Pipe joint

ABSTRACT

For use in the food-processing industry, a pipe coupling for flanged pipes, which provides a joint free from inside crevices (where food particles might lodge) comprises annular opposed grooves on confronting faces of the flanges which grooves partially surround a sealing ring disposed between them, the back faces of the flanges being pressed together by a resilient clamping ring.

United States Patent [191 Westberg [4 Oct. 16, 1973 PIPE JOINT [75]Inventor: Alvar Torsten Westberg, Sandviken,

Sweden [73] Assignee: Sandvikens Vernverks Aktiebolag,

Sandviken, Sweden 221 Filed: Dec. 6, 1971 21 Appl. No.: 205,123

[30] Foreign Application Priority Data Dec. 9, 1970 Sweden 16636/70 [52]US. Cl 285/336, 285/407, 285/419 [51] Int. Cl. F161 21/06 [58] Field ofSearch 285/336, 365, 366,

[56] References Cited UNITED STATES PATENTS 1/1966 Tomb et a1. 285/365 X2/1968 Abler 285/365 X 2,789,844 4/1957 Kessler 285/365 X 3,398,9788/1968 Gasche 3,669,474 6/1972 Bode 285/336 FOREIGN PATENTS ORAPPLICATIONS 418,750 3/1965 Switzerland 819,024 10/ l 951 Germany382,169 10/ 1932 Great Britain Primary Examiner-James R. Boler AssistantExaminer-Wayne L. Shedd AttorneyRalph B. Parker et a1.

[5 7] ABSTRACT For use in the food-processing industry, a pipe couplingfor flanged pipes, which provides a joint free from inside crevices(where food particles might lodge) comprises annular opposed grooves onconfronting faces of the flanges which grooves partially surround asealing ring disposed between them, the back faces of the flanges beingpressed together by a resilient clamping ring.

1 Claim, 3 Drawing Figures Patented Get. 16, 1973 3,765,707

PIPE JOINT The present invention relates to pipe joints of the typewherein the pipe ends have opposed flanges secured together by means ofa surrounding clamping ring (or equivalent device). The confrontingfaces of the flanges have annular opposed grooves which partly surrounda sealing ring accommodated between the grooves. The pipe joint of theinvention is especially meant for conduits in the food-productionindustry. In this connection a main demand is, and has been, that thecoupling shall be free from inside crevices, slots and cavities, wherefood fragments may lodge and colonies of bacteria ensue. A furtherrequirement is that the coupling should be easy to clean.

In the pipe joint according to the invention the grooves are thereforeapplied directly adjacent to the inner surfaces of the pipes so thatthere is formed a thin slit between them at the inner surfaces. Thesealing ring can to a certain extent protrude through the slit and inthat way prevent inside crevices or cavities. By having the grooves meetthe inner surface of the pipes in a practically sharp edge a goodsealing is secured. Also, between the opposed planes of the flangessituated outside the grooves there is usually formed a thin slit.

Hitherto known pipe joints of similar types have generally been made sothat the opposed planes of the two flanges, except for theearlier-mentioned slit, could be entirely brought together by means ofthe clamping ring resulting in a rigid joint. In order to make thenecessary clamping possible the back faces of the flanges usually hadbeen inclined so that they diverged inwardly. The surrounding clampingring had, then, an inwardly U-formed profile, and had been screwedtogether in order to clamp the flanges. When fast and simple mountingand dismounting have been required such pipe couplings have often beenunsatisfactory. The cost of the pipe joint has also been relatively highi.a. because of the requisite precision of the conical surfaces inflanges and clamping ring, and the necessity of screw joints or thelike.

The present invention provides a pipe joint which permits an extremelysimple and fast mounting and dismounting. The mounting may thus be donewithout any tools and the dismounting by means of a screw driver or thelike, in both cases by a simple motion of the hand.

In the coupling according to the invention the flanges are as aprinciple formed usually by simple, plain rings. The clamping ring,which generally consists of two clamps, is preferably made of mouldedplastics, and usually has no separate clamping means. This in its turnresults in a simplified and cheapened manufacture of the couplingcompared to hitherto used constructions.

The invention will be made clear from the following specific descriptiontaken in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal section of a part of a coupling according tothe invention;

FIG. 2 represents a clamping ring for the pipe joint; and

FIG. 3 shows one of the two clamps, which together form the clampingring according to FIG. 2.

In FIG. 1 there is shown a pipe coupling in which tube has a flange 11with an annular groove 12 and tube 13 in the same way has a flange l4and annular groove 15. The grooves lie alongside each other and togetherform a track which partly surrounds a sealing ring 16 consisting of anelastomer such as rubber or similar material. In the shown example thegrooves are V-shaped, and the sealing ring originally has a circularcross-section. Within the scope of the invention a variety of otherforms and types of grooves and sealing rings may exist, however. Theflanges l l and 14 consist of rings which are secured to the pipe endsby means of inside welds l7 and 18, respectively. The grooves meet theinner surfaces of the flanges in almost sharp edges 19 and 20,respectively, which edges tighten against sealing ring 16 protruding inthe slit between the rings.

The flanges are surrounded by a clamping ring 21 whose inner flanks 22and 23, respectively, substantially form a angle with the axis of thetube except from the ends where they are wedge-shaped. By means of thewedge-shaped parts the flanges are pressed together when the two clampsof the clamping ring are brought towards each other.

Because the contact surface between flange and clamping ring makes aright angle with the central axis of the tube neither the axial forcefrom the inner overpressure nor outer bending stresses can separate theclamps of the clamping ring. By the influence of the inner overpressurethe flanges are pressed, by means of the sealing ring against the innerflanks of the clamping ring securing a contact along the contact surfacejust mentioned.

In order to make a fast and simple application of the clamping ring overthe two flanges possible, the flanges may be, and usually are, so shapedthat a thin slit 24 is formed between the opposed planes of the flanges.By these means a certain movement or compression of the flanges towardseach other can take place when the clamping ring is applied.

FIG. 2 shows a clamping ring which consists of two clamps 25 and 26. Itsurrounds two flanges (not visible) of which one is fastened to tube 27.The clamps are made of a material whose mechanical properties includethe characteristic of a fast and complete recovery of form after abending of the joint. This means that the clamps can be held together bysimple locking devices 28 and 29, comprising resilient tongues 35, 36provided with hooks 30, 31 and which are conformably config ured to beaccomodated in notches 37, 38 in the clamping ring itself. In certaincases, for instances, in a clamping ring of steel, it has sometimes beenfound more advantageous to use one or more separate locking deviceswhich are applied to the clamping ring by welding or similar operation.

In the embodiment shown the one locking device forms a hingeT 30, 31 onwhich the clamps revolve in the course of being combined. If a suitablematerial (for instance, a formaldehyde plastic) is used in the clampsthe result may be that the joint cannot be separated by the hand alone,for instance by a mistake. On the other side, it is very simple to prythe clamps apart by means of a screw driver or similar pointed tool.

In FIG. 3 there is shown one of the two clamps which together form theclamping ring according to FIG. 2. The righthand clamp in FIG. 2 hasbeen turned 90 so that there is shown the part facing inwardly againstthe tube. From FIG. 3 it is seen that the inner flanks 32 and 33 of theclamps form a right angle with the axis of the tube except in their endswhere they are wedge-shaped. As was mentioned hereinbefore, the flangesare pressed together by means of the wedge-shaped parts 34, 34

when the clamps are brought towards each other.

The pipe joint of the present invention advantageously can be used forpressures in class NT6 and at a highest operating temperature of 100 C.In spite of being surrounded by a resilient clamping ring (21), whereinthe resilient clamping ring (21) consists of two principally equal partsor halves, preferably made of plastic, each comprising clamps (25, 26)and locking devices (28, 29) consisting of resilient tongues (35, 36)provided with hooks (30, 31) and corresponding notches (37, 38), theclamping ring parts or halves being designed to be brought together andlocked by pivoting motion of each clamping ring part, at which motionthe mentioned hook (30, 31) belonging to one half is supported in thementioned notch (37, 38) belonging to the other half, while theremaining hook and notch form a locking device at the final period ofthe pivoting motion.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 765,7 7 Dated Qctober l 1973 Inventor(s) Alvar' Torsten Westberg It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover sheet itemUB] the assignee 3 name should read as follows:

'-- Sandvik Aktiebolag Signed and sealedthis 30th day of 'April'lWLEDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer 'Q M PC4050 uscoMM-oc60376-P69 ".5. GOVERNMENT PRINTING OFFICE: ISIS 0-866-31,

1. A pipe joint comprising opposed flanges (11, 14) on the pipe ends(10, 13) the adjacent faces of which have annular opposed grooves (12,15) partly surrounding a sealing ring (16) accommodated between thegrooves, the back faces (22, 23) of the flanges being surrounded by aresilient clamping ring (21), wherein the resilient clamping ring (21)consists of two principally equal parts or halves, preferably made ofplastic, each comprising clamps (25, 26) and locking devices (28, 29)consisting of resilient tongues (35, 36) provided with hooks (30, 31)and corresponding notches (37, 38), the clamping ring parts or halvesbeing designed to be brought together and locked by pivoting motion ofeach clamping ring part, at which motion the mentioned hook (30, 31)belonging to one half is supported in the mentioned notch (37, 38)belonging to the other half, while the remaining hook and notch form alocking device at the final period of the pivoting motion.